Need some help with my 408 setup
Thread Starter
Burning Brakes
Joined: Feb 2007
Posts: 1,037
Likes: 0
From: Kansas City Missouri
St. Jude Donor '09
Need some help with my 408 setup
I posted this in tech but no views or luck there maybe someone here can help me.
Okay here is the skinny:
Awhile back I decided to take out my -15cc pistons and 72cc AFR 225's in favor of -2cc pistons with 62cc 215 ETP heads. Well here is the problem my pistons ended up coming out of the block so much that I had to run 2 x 3 layer MLS gaskets stacked on top of each other. So now I will be ordering some new heads. I was thinking of going with a 225 or 235 head this time around with a 58cc chamber and putting my -15cc pistons back in so I have optimal quench again. While I am at it I am going to be putting in a new camshaft 238/240 .605/.609 112 LSA in it. Now my question what is going to be my new compression ratio DCR and SCR and how much power do you estimate.
Setup:
408 Iron 4.030 bore 4.000 stroke
Gasket Cometic .040 thickness 4.030 bore
Pistons: -15cc Wiseco
Cam: 238/240 .605/.609 112 LSA on 110 centerline
Trickflow 225 or 235 with 58cc chambers (not sure which one I will take yet)
Old setup:
408 Iron 4.030 bore 4.000 stroke
Gasket: 2 x 3 Layer MLS
Pistons: -2cc Diamond (came out of block .100!!!)
Heads: ETP 215 62cc
Cam: 215/221 .631/.644 118 LSA
Car made 472hp/472tq
What do you think??? And lastly how do you feel my LS7 clutch is going to take it?
Okay here is the skinny:
Awhile back I decided to take out my -15cc pistons and 72cc AFR 225's in favor of -2cc pistons with 62cc 215 ETP heads. Well here is the problem my pistons ended up coming out of the block so much that I had to run 2 x 3 layer MLS gaskets stacked on top of each other. So now I will be ordering some new heads. I was thinking of going with a 225 or 235 head this time around with a 58cc chamber and putting my -15cc pistons back in so I have optimal quench again. While I am at it I am going to be putting in a new camshaft 238/240 .605/.609 112 LSA in it. Now my question what is going to be my new compression ratio DCR and SCR and how much power do you estimate.
Setup:
408 Iron 4.030 bore 4.000 stroke
Gasket Cometic .040 thickness 4.030 bore
Pistons: -15cc Wiseco
Cam: 238/240 .605/.609 112 LSA on 110 centerline
Trickflow 225 or 235 with 58cc chambers (not sure which one I will take yet)
Old setup:
408 Iron 4.030 bore 4.000 stroke
Gasket: 2 x 3 Layer MLS
Pistons: -2cc Diamond (came out of block .100!!!)
Heads: ETP 215 62cc
Cam: 215/221 .631/.644 118 LSA
Car made 472hp/472tq
What do you think??? And lastly how do you feel my LS7 clutch is going to take it?
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
With a "normal" out of the hole dimension...you should be right in the 11.5 SCR ballpark. I don't have Excel on this comp and can't calculate DCR right now, but I don't see it being a problem for pump gas.
I would choose the TF 225s for use with it.
The 235s are usually optimized for a 4.125" bore, and I think wouldn't work as well with your relatively mild cam choice. If it was an all-out drag car with a 25x/26x cam, my suggestion might be different.
Your proposed package sounds great, should make for a nice docile street car and with all the right intake/header goodies, I'd expect numbers in the 520rw ballpark.
The LS7 clutch seems to be hit/miss. Many people below your current hp level have had problems with it. yet some above 500 find it reliable. Makes it hard to gauge just what hp level it's really good to. If it were me with the engine out, I'd toss a dual disc in it for sure...but I have zero faith in GM (Luk) clutches, so I'm biased. If yours was working well at 472rwhp, it may work well with the new setup too.
I would choose the TF 225s for use with it.
The 235s are usually optimized for a 4.125" bore, and I think wouldn't work as well with your relatively mild cam choice. If it was an all-out drag car with a 25x/26x cam, my suggestion might be different.
Your proposed package sounds great, should make for a nice docile street car and with all the right intake/header goodies, I'd expect numbers in the 520rw ballpark.
The LS7 clutch seems to be hit/miss. Many people below your current hp level have had problems with it. yet some above 500 find it reliable. Makes it hard to gauge just what hp level it's really good to. If it were me with the engine out, I'd toss a dual disc in it for sure...but I have zero faith in GM (Luk) clutches, so I'm biased. If yours was working well at 472rwhp, it may work well with the new setup too.
Thread Starter
Burning Brakes
Joined: Feb 2007
Posts: 1,037
Likes: 0
From: Kansas City Missouri
St. Jude Donor '09
Well thanks for the comments. I am really loving the clutch right now and haven't had a problem. I just took out a problematic SPEC twin disc and am a little skeptical about it. Have to do quite a bit of stop and go and I'm pretty sure my left leg is twice as strong as the right now 
I don't all out race the car just some spirited driving is all and was just wondering what the point as to where the clutch just can't grab anymore.
I don't all out race the car just some spirited driving is all and was just wondering what the point as to where the clutch just can't grab anymore.
